As some of you know, I've been chasing down a wind noise issues ( now resolved ) on my X358 but wanted others thoughts...........
Have any of you had any issues with a little wind noise, perhaps the odd squeak or rattle here n there as well as road noise and decided to do anything about it?

I'm looking into / considering dynamat or similar for wheel wells, interior door panels, boot area and others to achieve the quietest ride possible.
Its only a thought process at the moment and something I'm looking into, so would appreciate any input from anyone who has also thought about it or done anything about it.
Thanks

 

Jim,

If you reduce exterior noise too much, how will you hear the crowds cheering as you drive by?

In our XJR, I wouldn't mind a little less wind and road noise and a little more engine noise....

Cheers,

Don

 

Lol, I hear you on the roaring crowds Don, still puts a smile on my face the amount of positive comments, bordering on sheer adulation that she gets, never gets old.

Road noise - I'm currently looking at a UK product called "Silentcoat" which is a sound deadening material range similar to dynamat I guess.
The plan is to start by applying it in the boot / trunk area as a test, then I'd like to move on to the door internals and hopefully wheel well liners too.

If / when I get around to it, of course I'll post any findings / results either way

 

This gave me a good laugh

 

Hi Jim,

I run silent coat in mine ( the boot area was resonating badly with the sub installed) as a lifelong user of dynamat xtreme and 8 years in car audio (previous job) I can say that the silent coat product is every bit as good, the real bonus is the price as its significantly cheaper! Just remember the 90/10 rule when installing it , you can get 90 % effectiveness with only 10 % product by installing strips of the product as opposed to covering everything. If I can be of assistance let me know, cheers.

 

Thanks John, appreciate the feedback
Have you applied t anywhere else or just the boot area?

 

Just the boot area and rear shelf (which also resonated) at the moment, the rest of the car wasn't too bad but I may put some around the door handles as they seem to rattle when the bass is thumping.

 

Hey John, still toying with this idea and checked out Silentcoat Vibrodamping 2mm thick and also considering adding some Dodo liner CCF6 Closed cell foam on top.

My rear shelf also resonates a little ( nothing major but a little here n there, more than a little annoying.
So I'm thinking the rear boot area, spare well etc and considering removing the interior carpeting on the sidewalls etc too ( need to check this out ) then also on the underside of the rear shelf.

I've also thought about removing the bonnet liner and adding it under there too, just to see what difference it makes.
Thoughts?

 

My car sneaks up on pedestrians and scares the c^&p our of them as it is. I can't imagine making it quieter.

 

Same here. And I really didn't realize how quiet the car was on the inside until I drove it back to back with my Acura TL. There is a HUGE difference!

 

I would definitely do both sides of the rear shelf as it does improve the sound, I have done the spare wheel well as well as both sides of the rear seat support (metal) and removed a ski hatch type of panel that was present to allow the low frequencies an easier path out of the boot, I've got some pics somewhere I'll dig them out. As far as the foam goes that is normally used directly behind a speaker, eg in the lower sections of the doors and I don't think you would see a significant gain when compared to using just the matting.

Under bonnet again not sure there will be a perceivable gain as the engine bay area is quite well sealed, can't hear my engine when the bonnets up let alone down lol.

 

I thought I had taken more photos of this part of the process however it appears I didn't, in anycase here's some pics.



Rear shelf after stripping rear seat/ parcel shelf trim.



Rear shelf after.



Inside the boot, you can see the silver 'ski hatch' panel that I later removed.



That's as far as my photos go obviously spent a load of time on the boot lid itself and must admit it took 2 coats in some areas to get that to stop resonating!

 

Nice one John, thanks for sharing, why do you live so far away??....lol

 

As one who worked for one of the Big 3 in another life, cabin noise is reduced in 3 major areas. Firewall, outside door skin, floor. Since carpet and batting does some good already, next is exterior door skin. Then interior door panel. And since most firewalls have some, this may prove less effective. Make sure you address tunnel areas under the console. And lastly, boot areas are addressed like door skin. Exterior skin is of highest resonance in those frequencies we deem as "noisy." The roof is an area many do not do. Sit inside and have someone tap their finger on areas around the vehicle to help you determine areas you wish to concern yourself with first.

 

I have rushing air noise from the sunroof area. It appears to close correctly but question if it may stick up a bit or?

 

I'm sure I've seen / read several posts on this issue on the forum, with solutions too. Do a search and I'm sure they'll pop up.
Good luck

 

I've downloaded an App called "Sound meter" which as it sounds like, is a decibel meter.
My plan is when time allows, to make some motorway type runs, hopefully get one of the boys to assist by sitting in the rear, using the App to make some base readings from that area initially.
I'll ask them to take some readings of the general area, then in particular the rear shelf area, as well as the rear window area.

This should give me some base readings, an idea of where I am and a base to work from.
The tape up some of the areas I think may be causing the problem and do runs on the same stretch of road, same speed etc and see what / if any differences there are.
Unsure if I'll be able to entice them to lay in a locked trunk / boot area and do the same tests though?....lol

I'll keep you posted.............

 

Well, Peter helped me tonight and we had a little play around, we did some base runs at 70mph / 80mph and 100mph initially and took readings

Inside the interior of the cabin was reading at around 64db, then we concentrated on the front edge and rear edge of the rear windows passenger side and drivers side
They came back at around 68db leading edge and 73db-74db on the rear of the rear window


I should add to start with ( perhaps some of you could check? )
Re the rear door frame - the seal that surrounds the door frame doesn't quite meet, on both sides, although the drivers side seems a bigger gap ) and I was convinced this was partially my issue, so.....
As per pic below, I taped up the seal at the missing section, same area both sides and did a run at 70, 80 and 100mph


The cabin noise seemed similar overall, but there did seem a 1-2db reduction after this, I think I may fill this area with black silicone temporarily to see if that helps somewhat.

Next, Peter seemed convinced that he rear quarter window was the problem area, tests seemed to show that the leading edge of the rear window was 68db but the rear edge was at around 73db-74db, so we taped off the inside of the rear quarter window and did the same runs, at the same speeds over the same section of road


I'd really like to say that there was a definite reduction, but in truth the results were almost inconclusive!

Lastly, running out of gaffer tape ( lol ) we taped off the pillars where the front door meets the rear, up and over the door framework and down the rear edge of the rear door, as per the pic below....


In all honesty, there seemed little to no difference!
It seems that we achieved nothing, except to perhaps rule these areas out of the equasion?


I'm now considering window seals as something to check.

Over and above this I will be having new tyres fitted shortly so we'll see if that makes a difference, although my tyres are anything but worn.
Another thing I hope to be doing soon is removing the boot / trunk carpeting etc and adding both sound deadening and Mass loaded vinyl / closed cell foam to act as acoustic barriers.
The plan is to cover the entire boot area, sidewalls and pay special attention to the wheel arch areas extending to and including the rear parcel shelf area too.

My hope is that this will have a positive effect.
Any comments / helpful suggestions welcomed
Thanks

 

Moving forward with this, I used a method as seen in the video below.
Inserting a coupon, piece of A4 paper between the door and frame, assuming the seals do their thing, there should be some resistance.....there was none.

<iframe width="854" height="480" src="https://www.youtube.com/embed/Egvfsf6cw7Q" frameborder="0" allowfullscreen></iframe>

I've ordered some 3M add on door seal and am waiting for it to arrive. the plan is to add to the existing door seal as shown and see what if any difference there is.
Over and above that as shown in the next video is a smaller 3M add on seal applied as shown to the door.

 

Shown below is the slightly smaller add on 3M door seal for the door itself.

<iframe width="854" height="480" src="https://www.youtube.com/embed/_PCbFrLfJ-U" frameborder="0" allowfullscreen></iframe>

I'm going to add this also and see what, if any difference is made.
The hope is that it helps to reduce any wind noise of course. I've also small droplets of moisture that ice up making all doors freeze easily in relatively cold weather.....even on the drivers door with the brand NEW OEM seals!

I'll see how this goes and report back, here's hoping for positive results before I add the sound deadening in the boot and rear wheel arch areas to reduce road noise.
All In the quest for a quieter car, just trying to improve the overall experience a little further.
I'll report back of course either way....